#include "node_counters.h"
#include "uv.h"
#include "env.h"
#include "env-inl.h"

#include <string.h>

namespace node {

using v8::FunctionCallbackInfo;
using v8::FunctionTemplate;
using v8::GCCallbackFlags;
using v8::GCType;
using v8::HandleScope;
using v8::Isolate;
using v8::Local;
using v8::Object;
using v8::String;
using v8::Value;

static uint64_t counter_gc_start_time;
static uint64_t counter_gc_end_time;

void COUNTER_NET_SERVER_CONNECTION(const FunctionCallbackInfo<Value>&)
{
    NODE_COUNT_SERVER_CONN_OPEN();
}

void COUNTER_NET_SERVER_CONNECTION_CLOSE(const FunctionCallbackInfo<Value>&)
{
    NODE_COUNT_SERVER_CONN_CLOSE();
}

void COUNTER_HTTP_SERVER_REQUEST(const FunctionCallbackInfo<Value>&)
{
    NODE_COUNT_HTTP_SERVER_REQUEST();
}

void COUNTER_HTTP_SERVER_RESPONSE(const FunctionCallbackInfo<Value>&)
{
    NODE_COUNT_HTTP_SERVER_RESPONSE();
}

void COUNTER_HTTP_CLIENT_REQUEST(const FunctionCallbackInfo<Value>&)
{
    NODE_COUNT_HTTP_CLIENT_REQUEST();
}

void COUNTER_HTTP_CLIENT_RESPONSE(const FunctionCallbackInfo<Value>&)
{
    NODE_COUNT_HTTP_CLIENT_RESPONSE();
}

static void counter_gc_start(Isolate* isolate,
    GCType type,
    GCCallbackFlags flags)
{
    counter_gc_start_time = NODE_COUNT_GET_GC_RAWTIME();
}

static void counter_gc_done(Isolate* isolate,
    GCType type,
    GCCallbackFlags flags)
{
    uint64_t endgc = NODE_COUNT_GET_GC_RAWTIME();
    if (endgc != 0) {
        uint64_t totalperiod = endgc - counter_gc_end_time;
        uint64_t gcperiod = endgc - counter_gc_start_time;

        if (totalperiod > 0) {
            unsigned int percent = static_cast<unsigned int>(
                (gcperiod * 100) / totalperiod);

            NODE_COUNT_GC_PERCENTTIME(percent);
            counter_gc_end_time = endgc;
        }
    }
}

void InitPerfCounters(Environment* env, Local<Object> target)
{
    HandleScope scope(env->isolate());

    static struct {
        const char* name;
        void (*func)(const FunctionCallbackInfo<Value>&);
    } tab[] = {
#define NODE_PROBE(name) #name, name
        { NODE_PROBE(COUNTER_NET_SERVER_CONNECTION) },
        { NODE_PROBE(COUNTER_NET_SERVER_CONNECTION_CLOSE) },
        { NODE_PROBE(COUNTER_HTTP_SERVER_REQUEST) },
        { NODE_PROBE(COUNTER_HTTP_SERVER_RESPONSE) },
        { NODE_PROBE(COUNTER_HTTP_CLIENT_REQUEST) },
        { NODE_PROBE(COUNTER_HTTP_CLIENT_RESPONSE) }
#undef NODE_PROBE
    };

    for (size_t i = 0; i < arraysize(tab); i++) {
        Local<String> key = OneByteString(env->isolate(), tab[i].name);
        Local<Value> val = env->NewFunctionTemplate(tab[i].func)->GetFunction();
        target->Set(key, val);
    }

#if defined(WIN32)
    // Only Windows performance counters supported
    // To enable other OS, use conditional compilation here
    InitPerfCountersWin32();
#endif
    // init times for GC percent calculation and hook callbacks
    counter_gc_start_time = NODE_COUNT_GET_GC_RAWTIME();
    counter_gc_end_time = counter_gc_start_time;

    env->isolate()->AddGCPrologueCallback(counter_gc_start);
    env->isolate()->AddGCEpilogueCallback(counter_gc_done);
}

void TermPerfCounters(Local<Object> target)
{
#if defined(WIN32)
    // Only Windows performance counters supported
    // To enable other OS, use conditional compilation here
    TermPerfCountersWin32();
#endif
}

} // namespace node
